On the other hand, the boundary conditions for mechanical equilibrium are imposed within the hydrogel domain only.
Both the converged concentrations and electric potential are in turn substituted into the mechanical equilibrium equation (4) for computing the corresponding hydrogel displacement u.
Using the finite deformation formula governing the mechanical equilibrium, the MECpH model has been improved.
In practice, the force balance described above is decomposed into area-independent and area-dependent terms and solved numerically with standard relations arising from mechanical equilibrium
(Evans and Skalak, 1980).
Newmann Triangle: The Neumann triangle or sessile drop method is very similar to the pendant drop method, consisting of the study of the profile of a drop of one liquid resting on a flat plate surrounded by another liquid of smaller density (in the case of the determination of interfacial tension) or by air (in the case of determination of surface tension) at mechanical equilibrium.
The samples were left in an argon atmosphere until mechanical equilibrium was reached (around 8 hours).